Traumatic Life Events and Association With Depression, Anxiety, and Somatization Symptoms in Female Refugees

Key Points Question Which traumatic life events are associated with current depression, anxiety, and somatization symptoms in female refugees seeking psychological help? Findings In this cross-sectional study of 620 female refugees, by use of random forest regression, family violence had the highest scores associated with depression, anxiety, and somatization, beyond cumulative trauma exposure. These scores were higher than those for more frequently reported traumatic events, such as war, accident, lack of housing, hunger, and near death. Meaning These findings suggest that even for women with a history of multiple traumatic experiences, understanding the impact and likelihood of family violence is vital in diagnostic assessments and informing treatment strategies.


Introduction
The displacement of people from their countries through war and conflict, owing to direct threats to individual lives and famines, has increased continually in the last decade, with more than 80 million displaced persons recorded in 2020. 1 Germany experienced a major influx of refugees and asylum seekers beginning in 2015, 2 primarily owing to the Syrian civil war, as well as other conflicts and humanitarian crises in the Middle East and North Africa. At the time of this writing in 2023, a new wave of refugees is fleeing war in Ukraine. 3 Many refugees experience repeated traumatic events, physical and sexual violence, torture and imprisonment, and witnessing the death of loved ones, as well as frequent interpersonal violence, including emotional, physical, and sexual abuse. 4 These experiences increase the risk of a wide variety of mental health issues, including posttraumatic stress disorder (PTSD), depression, anxiety, and somatization. 5,6 Given the scale of this epidemiological trend, it is imperative to better map the occurrence of mental health problems and their exposurebased antecedents to evaluate risks in diagnostic assessments and optimize treatment interventions.
A challenge of understanding the exposure-based antecedents of mental illness in refugee populations is finding a way to group the data. A dose-response relationship can be demonstrated across different clusters of psychopathology symptoms by summing different types of traumatic life events. This building block effect, as seen in PTSD, 7,8 where traumatic experiences are part of the definition and cause of the disorder, has also been shown to be relevant in depression and anxiety [9][10][11] and in somatization. 12 However, this simplification of the data has the disadvantage of missing differences in the impacts of the types of traumatic events. Other studies have focused on one type of life event, such as studies showing that intimate partner violence is associated with depression. 13 Although these findings are valid within the scope of the respective studies, there is a disadvantage in that the broader context of the individual's life is not accounted for. For example, within refugee populations, somatization [14][15][16] is associated with previous traumatic experiences, 17 childhood sexual abuse (CSA) in particular. [18][19][20] However, we do not know whether this is a primary factor, or if it is instead associated with other later traumatic events, such as domestic violence or personal injury.
One way of reducing the complexity of the picture is by clustering different types of traumatic events. For example, in a study 12 of depression, anxiety, and somatization, trauma was categorized according to human rights abuses, human needs, separation, and traumatic loss. Following this approach, many studies 21-24 make a distinction between assaultive, human-made violence, natural disasters, accidents, or witnessing violence in others. In the present study, we use a different, more data-driven approach to simultaneously examine individual traumatic experiences and their cumulative impact on symptoms. We interviewed a large group of female refugees, the majority of whom were fleeing war in Syria and Afghanistan; however, there were also others from North Africa and other Middle Eastern countries. As such, these women experienced extremes of human suffering, including war, torture, displacement, and sexual and gender-based violence. 25 Our question was whether their symptom levels were primarily associated with the cumulative impact of multiple trauma, or whether particular traumatic experiences had a greater impact on their current state. 26,27 We do not know which events have the greatest impact on their present levels of depression, anxiety, or somatization, beyond the cumulative impact of their traumatic experiences.
Furthermore, although these symptoms cluster together, 12,27 it is possible that the different expression of symptoms is associated with different types of events. However, this is important to better understand refugees, target interventions, and, ultimately, help with integration in the host society.
The present study uses random forest regression to comprehensively evaluate factors associated with symptoms of anxiety, depression, and somatization in refugee women with various forms of risks and cultural backgrounds. 28 This enables a fine-grained analysis of the impact of individual events possible, even in smaller sample sizes, by allowing the simultaneous consideration of risks in association with symptoms of mental health. 29 This approach has already been applied to PTSD and aggression. 30,31 By identifying the most important variables accounting for symptoms, we further test potential mediations between variables of importance (VIMs).

Recruitment
This cross-sectional study was a joint project (The Study on Female Refugees) conducted in 2016 with 5 locations in 5 provinces in Germany: Berlin (the capital city), Mainz in Rhineland-Palatinate, Nuremberg in Bavaria, Rostock in Mecklenburg-Western Pomerania, and Frankfurt in Hesse. All project partners sought and obtained ethical approval within their institution of reference (university or region, depending on the regional law). All procedures complied with the declaration of Helsinki. 32 This study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline.
Participants were recruited at the reception centers for refugees in collaboration with facility management. The project was introduced via a 1.5-hour information event presented by native speakers of Arabic, Dari or Farsi, Somali, and Tigrinya, followed up by flyers in the respective languages. Women (aged Ն18 years) who were interested were interviewed privately at reception facilities after at least a 1-day interval. Informed consent was obtained in either written form or in oral form, if the participant was illiterate. Waivers of consent were not required. Interviews were conducted in the participants' native language by trained women. The interviewers' qualifications and degrees ranged from student status to doctorate degree. They received a 1.

Measures
The measures were part of a questionnaire battery. 4,11 We used the Harvard Trauma Questionnaire The original qualitative data on these aspects were simplified for compatibility with the random forest procedure (see the Statistical Analysis subsection). These included marital status (in a relationship or alone), country of origin, education level (no school, school, or tertiary education), religion (Islam, Christian, or other), children (yes or no), and age.

Statistical Analysis
The current analysis was conducted in 2022 to 2023. To test the associations of current symptoms (depression, anxiety, and somatization) with traumatic life events, together with demographic factors, the machine learning technique conditioned random forest regression was used. 30 Conventional multiple regression would not be appropriate for the analysis, because there are many variables, even relative to our large data set, with high multicollinearity. A random forest regression does not require variables to be normally distributed; the number of variables can, in principle, exceed the number of data points, and the decision tree structure can account for interactions between variables. Thus, the power of our sample size is adequate to this form of analysis. The  37 This has been used previously 38 and has further refinements to remove biases from the importance resulting from number of categories, mean values, range, or variance in independent variables. The script was based on the procedure described by Schalinski et al. 39 The training and testing models used 10 repetitions of 10-fold cross-validation. Nine of the 10 sets are used to generate the model, which is then tested on the 10th set. This is repeated 10 times, so that each set tests the validity of the model. This whole process is repeated 10 times on different random sets of the data. The results provide 95% CIs and P value estimates for each independent variable. Although the algorithm is robust to collinearity in independent variables, it is not possible to directly test associations between independent variables as one would with standard parametric statistical analyses. Therefore, once VIMs were defined, we performed exploratory follow-up analyses examining the associations between these independent variables. Where 2 categories of traumatic experiences are associated with depression, it is possible that the more proximate one mediates the less proximate one. We tested this with mediation analyses of VIMs via the Mediation package in R. 40 Mediation effects were tested with bootstrapping (1000 samples), estimating explained variance over the indirect path, with 95% CIs. To ensure adequate power, we checked the crosstabulation of risk factors of interest to ensure a minimum of responses in each cell; the smallest cell across all analyses was 27.

Descriptive Statistics
In

Random Forest Analyses
The random-forest regressions for depression, anxiety, and somatization yielded both common and differential factors associated with traumatic life events and demographic characteristics (Figure 1).

Follow-Up Analyses
The identified VIMs show the importance of family violence across depression, anxiety, and somatization. However, family violence could have complex associations with other VIMs. Therefore, we tested potential mediation models. For both depression and anxiety, both CSA and family violence were VIMs. If CSA is a factor associated with adult relationship problems, its association with depression or anxiety and depression could be mediated by more recent family violence. However, both factors were independently associated with depression and anxiety, with small partial mediation effects (Figure 2A). The indirect path accounted for 8.0% (95% CI, 3.2%-13.0%; P < .001) of variance in depression and 10.8% (95% CI, 4.5%-10.8%; P < .001) of variance in anxiety. Both somatization and anxiety were associated with family violence and physical injury (Figure 2A). The effect of family violence on symptom scores could be indirectly associated with physical injury.

Discussion
The aim of this cross-sectional study was to simultaneously examine individual types of traumatic events, as well as the cumulative impact of trauma, to see which have the greatest impact on current depression, anxiety, and somatization symptoms in a group of refugee women. This study supports     Both depression and anxiety showed many commonalities in contributing factors, including CSA, lack of health care access, and near death experiences. Anxiety scores were also associated with witnessing torture. For somatization, illness without access to health care and injury were important.

JAMA Network Open | Psychiatry
The types of family violence encompassed include chronic abuse from a spouse, as well as individual attacks by family members. It is possible that physical injury is a direct follow-on effect of family violence; however, mediation analyses found partial indirect effects, in which family violence contributed directly to anxiety and depression, independently of physical injury. Similarly, our follow-up analyses of family violence as a potential mediating factor associated with CSA, showed that both family violence and CSA were independently associated with symptoms.
This study provides a comprehensive picture of the impact of a wide range of life events and shows that family violence has a great impact on symptoms overall. It is necessary to follow-up these findings further using longitudinal study designs and cross-lag analyses, which would help identify  Panel A depicts whether the association of childhood sexual abuse (CSA) with depression and anxiety was mediated by family violence (self). Both independent variables contributed main effects to the respective symptoms, with a partial mediation effect (in square brackets). Panel B shows that the association with family violence (self) was mediated by high levels of injury, explaining variance in both anxiety and somatization. Both independent variables contributed main effects to the respective symptoms, with a partial mediation effect (in square brackets). PC indicates path coefficient. stable associations of exposure risks with psychopathology. Family violence is a potentially more immediate part of the current postmigration existence. There is a connection between experiences of war and violence in the home. 42 For example, a study 43 of Iraqi refugees showed that recent experiences of domestic violence were associated with the psychopathology of the male partner (PTSD and depression), as well as cultural attitudes. Other factors, such as substance abuse, destabilization of customs, and breakdown of social and familial bonds, could also contribute to a greater impact of family-related violence. 44 Understanding the centrality of family violence is important in treating vulnerable minority groups, because they already have problems accessing adequate health care in their host countries. 45 Despite limited access to health infrastructure, refugees have legal rights to particular forms of care, including gynecologists and other obstetric health professionals, such as midwives, as well as inpatient obstetrics and pediatric centers. This could be a means of reaching these women, providing direct emotional support, as well as referring them to counseling, shelter, or legal aid.
Training initiatives for social workers in the shelters and health care professionals to deal with the taboo aspect of domestic violence to facilitate such a protective framework are important. 46,47

Limitations
This study has limitations that should be mentioned. Our approach gave a broad picture of questionnaire-based symptoms of a large population sample, rather than clinical diagnoses.
Additional assessment of PTSD symptoms might have provided a more rounded picture of the symptom profile, since many participants had high levels of trauma experiences (mean, 5.68 experiences), which is factor associated with PTSD, 7 and anxiety, depression, and somatization form part of this constellation of symptoms. 48 Levels of medication, particularly psychopharmaceutical help, would also enrich the picture of the data. In addition, our recruitment method could not ensure a randomized sample, as participation was driven by the interest of female volunteers, limiting the generalizability of our findings beyond those seeking help.

Conclusions
The present study provides insights into the most important factors associated with increase risk of trauma in a large help-seeking sample of female refugees. Beyond the cumulative amount of trauma, exposure to family violence appears to be the key factor associated with risk of current symptoms of anxiety, depression, and somatization. Thus, the diagnostic assessment of exposure to trauma types may be relevant to identify women with increased risk for psychopathology, assign specific interventions addressing family violence, and, thereby, optimize treatment outcomes.